Voltage adjusting means for X-ray machines



VOLTAGE ADJUSTING MEANS FOR X-RAY MACHINES' Filed Nov. 5, 1937 3 Sheets-Sheet l" Dec. 13, 1938. E. J. RlEs 2,140,393

VOLTAGE ADJUSTING MEANS FOR X-RAY MACHINESA Filed Nov. 3, 1937 3 VSheets-Sheet 2'.

fave/fors 7d/ward Tf1-72.65

Dec. 13, 1938. E4 R155 v2,140,393

VOLTAGE ADJUSTING MEANS FOR X-RAY MACHINES Filed Nov. 5,1957 3 Sheets-Sheet 3 Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE VOLTAGE ADJUST'ING MEANS FOR X-RAY MACHINES of Rochester, N. Y.

Application May 3, 1937, Serial No. 140,342 In Germany December 17, 1936 12 Claims.

The present invention relates to an X-ray apparatus and particularly to X-ray apparatus in which the X-ray tube is arranged in a movable housing. X-ray apparatus of this type is usually connected to an alternating current supply circuit. The Voltage of the alternating current circuit, however, is different at different points of consumption and may vary, for example, between the limits of and 250 volts. To take care of this wide difference in voltage the primary winding of the transformer of the X-ray tube is provided with taps so that the supply circuit may be connected by means of an ordinary screw terminal to the particular one of the taps which corresponds to the normal voltage of the supply circuit at the place of installation of the X-ray apparatus, for example 110, 220 or 250 volts. In this manner, the X-ray apparatus is adjusted generally in accordance with the normal voltage of the supply circuit at the particular place of installation.

However, it is necessary to compensate for normal variations of the voltage of the supply circuit. If itis assumed that a supply circuit of 220 volts is connected to the 220 volt tap of the primary winding of the X-ray tube transformer, then if the Voltage of the supply circuit would remain exactly constant at 220 volts, no further adjustment would be required. Supply circuits are ordinarily subject to permissible variations of Voltage of 5% which, in reality, are usually doubled. In X-ray apparatus used for dental purposes, which is often connected to already overloaded circuits, these variations are frequently increased to 20% during the operation of the apparatus.

In order to compensate for these variations of the normal supply circuit voltage, it is common practice to connect a special auto transformer ahead of the conventional transformer, which converts the voltage of the alternating current source into the high voltage that is required for operation of the X-ray tube. These variations of voltage are compensated for by adjusting the auto transformer. The addition of the auto transformer, however, increases the cost of the X-ray apparatus, and the incorporation of the auto transformer requires an enlarged housing and, furthermore, increases the weight of the X-ray apparatus. This enlargement of the housing and increase in weight of the apparatus are of great disadvantage in apparatus used for dental purposes since the operator must frequently adjust the X-ray apparatus that is suspended from a standard.

(Cl. Z50-93) An important object of the present invention is to eliminate the necessity for the use of a device separate from the main transformer, that is used to energize the X-ray tube, for compensating for slight variations in line Voltage which are undesirable in operating the X-ray tube.

Ano-ther important object of the invention is to provide for adjusting the connection of the primary winding of a transformer, that is connected to energize an X-ray tube, to an alternating cur- 10 rent circuit in a plurality of small steps to compensate for Variations in the voltage of the alternating current circuit.

An object of the invention is to incorporate in an X-ray tube housing that is movably mount- 15 ed, such as for use by a dentist, the transformer for energizing the X-ray tube together with a simple and readily adjustable means for compensating for slight variations in line voltage which requires a minimum of space and has little weight.

Other objects of the invention Will, in part, be obvious and in part appear hereinafter.

The invention, accordingly, is disclosed in the embodiment hereof shown in the accompanying 25 drawings, and it comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the application of which will be indicated in the appended claims.

For a `more complete understanding of the nature and scope of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawings, in which:

Figure 1 is a view, in side elevation, of the X-ray apparatus;

Figure 2 is a view at an enlarged scale of a portion of the X-ray apparatus shown in Figure 1, certain parts being broken away to more clearly illustrate the invention;

Figure 3 is a sectional view taken along the line 3 3 of Figure 2;

Figure 4 is a perspective View, on an enlarged scale, showing the arrangement of the gear wheels that are employed in adjusting the taps on the primary Winding of the transformer;

Figure 5- is a detail sectional view taken along the line 5 5 of Figure 4; 50

Figure 6 is a perspective view of the adjusting ring; and

Figure 'l illustrates, diagrammatically, the circuit connections that may be employed in practicing the present invention. 55

In order to avoid the foregoing described disadvantages, a group of taps is provided on the primary winding of the X-ray tube transformer, in accordance with the present invention, with at least one manually operated adjusting member controlling a regulating device by means of which one terminal of the circuit may be selectively connected to each of the single taps of the group. This arrangement eliminates the necessity for a separate auto transformer since the differences in the voltage of the supply circuit may be taken care of by corresponding adjustment of the regulating device through the operation of the manual adjusting member. In this manner, an increase in the size of the X-ray apparatus housing is unnecessary, as is otherwise the case when a separate auto transformer is employed, and at the same time there is a corresponding decrease in the weight of the apparatus.

Referring now to the drawings, it will be ob served that the lower portion I (Figure 1) of the housing 2 is provided for carrying the Xray tube 3 (Figure 7) and that a tubus 4 extends therefrom. In the upper portion 5 of the housing 2 the transformer, shown generally at 6 in Figure 7, is mounted having a primary winding 1 and a secondary winding 8. The transformer 6 is immersed in oil which is contained within the upper portion 5 of the housing 2. Conductors 9 and I9 lead in a well known manner from the secondary winding 8 to the cathode of the X-ray tube 3 while the conductor II leads from the secondary winding 8 to the anode of the tube 3.

The upper portion 5 of the housing 2 is provided on top with a tubular section I 2. A flanged member I3 of a plug I5, having a central bore I4 is secured to this tubular stud by means of screws IB. A ilange I1 is provided at the lower portion of the hollow plug l5. A cylindrical portion I8, serving as a supporting element, is provided between the two flanges I3 and I1. By means of the supporting element I8 of the hollow plug I5, the entire housing 2 is rotatably mounted in a well known manner upon a standard (not shown) so that the housing 2 and apparatus contained therein may be pivoted about the axis of the hollow plug I5.

In the lower portion of the hollow space I9, Figure 2, of the tubular section I2, an insulating disc 20 is secured which engages with its oifset portion 2I an internal flange 22 of the tubular section I2. The insulating disc 20 is provided with a recess 23 that is open at the top and is dened at the bottom by a bottom plate portion 24.. The hollow space I9 is closed off from the upper portion 5 of the housing that is lled with oil by means of the insulating disc 20. The bottom plate portion 24 of the insulating disc 20 is provided with a ring of, for example, nine contact members 25 that are connected by means of ordinary screw terminals 61 with nine taps 1a to 1i at the left hand end of the primary winding 1 of the transformer E, as viewed in Figure '1, by means of separate conductors 26. The taps 1a to 1i provide for compensating for slight diiferences of voltage, for example, differences between 200 volts and 240 volts.

A sheet metal mounting plate 21, shown more clearly in Figure 4, is secured to the flange 22 by means of screws which `extend through holes 28 in this plate. A shaft 29 of insulating material, such as hard rubber, is mounted upon the plate 21', coaxially with the above described plug I 5. Above plate 21 a gear wheel 38 is secured to the 'insulating shaft 29. The portion of the shaft 29 extending below the plate 21 is rigidly connected with a metal stud 3i that is rotatably arranged upon a contact member 32 which is stationarily mounted in the bottom portion 24 of the disc 20. The contact member 32 is connected by a conductor 33 with a terminal member 34 that is positioned outside of the ring of contact members 25 which are mounted on the insulating disc 20.

A conductor 35, extending through bore I4, Figure 2, leads from the terminal member 34 to one slip ring 31 of three slip rings 36, 31 and 38 which are provided at the upper portion of the hollow plug I5. The slip rings 36, 31 and 38 are insulated from each other by insulating rings 39 and they are also insulated from the ange I1 of the plug I5. A conductor 40, extending through bore I4, leads from the slip ring 36 to a second terminal member 4I that is disposed outside of the ring of contact members 25 on the insulating disc 20 and which is connected by means of a conductor 42 and the described terminals 51 to one or the other of the two taps 1k or 1m at the right hand end of the primary winding 1, as viewed in Figure '1.

The conductor 42 is connected to either tap 1k or 1m depending upon the Voltage of the supply circuit at the place of installation of the X-ray apparatus. If the voltage of the supply circuit is 220 volts, the conductor 42 is connected to tap 1k. If the normal voltage of the supply circuit is 250 volts, then conductor 42 is connected to tap 1m. If desired, a plurality of taps may be provided at the right hand end of the primary winding 1 in order to permit connection of the conductor 42 to a tap of the primary winding corresponding to other supply circuit voltages, such as a voltage 110 volts.

From the slip ring 38 a conductor 43, extending through bore I4, leads to a third terminal member 44 that is positioned outside of the ring of contact members 25 on the insulating disc 20. The terminal member 44 is connected by a conductor 45 to one terminal of a milliammeter S8 connected between the two halves of the secondary winding 8. The purpose of the three slip rings 3E, 31 and 38 will be described in more detail hereinafter. The terminal members 34, 4I and 44 also form screw terminals to permit easy connection of the conductors described hereinbefore thereto. In the circuit diagram shown in Figure 7 of the drawings, the conductors 35, 40 and 43 are externally connected to the slip rings 36, 31, and 38 to more clearly illustrate the invention.

A contact arm 46 is carried by the metal stud 3I and rotates with the shaft 29. As shown, it is provided with a spring pressed sliding contact member 41. When the arm 46 swings about the axis of the shaft 29, the sliding contact member 4B comes successively into contact engagement with the contact members 25 that are carried by the insulating disc 20.

A stud 48 is mounted on the plate 21, Figure 4, for rotatably mounting a gear wheel 49. The gear wheel 49 meshes with gear wheel 30 and also with teeth 50 that are provided on the inner periphery of a manually operated adjusting ring 5I, Figure 6. The adjusting ring 5I is rotatably mounted within a recess 52 that is provided near the upper end of the tubular section I 2. In order to effect engagement of the gear wheel 49 with the teeth 50, a recess 53, Figure 3, is provided at the upper end thereof. A positioning ball is movably mounted in a cross-bore 54 and a spring 56 biases the ball 55 into engagement with one of a plurality of notches 51 in the inner periphery of the adjusting ring I, depen-ding upon its position. A stop 58 is mounted on the tubular section I2 for engaging the ends of a recess 59 in the adjusting ring 5I, thereby limiting its rotation in either direction.

Referring particularly to Figure 6 of the drawings, it will be observed that numerals I through 9 are indicated upon the outer surface of the adjusting ring 5I to permit a definite setting thereof with respect to an index marking 60 on fiange I3, Figure l. The numerals through 9 correspond to the nine contact members 25 and to the notches 51.

The three rings 36, 31 and 38, which are arranged above the support section I8, cooperate with contact ngers 6I, 62 and 63 respectively. These contact ngers are arranged in the standard (not shown) that carries the X-ray apparatus. The -contact ngers 6I and 62 are connected by conductors 64 and 65, respectively, with the terminals of the alternating current supply circuit while the contact nger 63 is connected to ground by a conductor 66.

In describing the operation of the invention herein disclosed it will be assumed that a normal alternating current supply circuit voltage of 220 volts is available at the place where the X-ray apparatus is installed. The conductor 42 is then connected to tap 1k and the adjusting ring 5I is positioned so that the contact member 41 carried by the arm 46 engages the iifth contact member 25 or that contact member numbered 5 in Figure 7 of the drawings. This adjustment of the parts corresponds to the operation of the X-ray apparatus when a normal supply circuit voltage of 220 volts is available. The circuit may be traced from conductor 65 through contact finger 62, slip ring 31, conductor 35, terminal member 34, conductor 33, contact 32, Figure 5, contact arm 46, fth Contact member 25, corresponding conductor 26, tap 1e; a portion of the primary winding 1 between the tap 1e and the tap 1k, conductor 42, terminal member 4I, conductor 40, slip ring 36, contact iinger 6I, to conductor 64.

If the voltage of the supply circuit is higher than normal, such as is the case before and after peak periods of the day, the Contact arm 46 is moved by means of the adjusting ring 5I from the 'fth position in a counterclockwise direction, as viewed in Figure 7. That is, the movement is in the direction of the first contact member 25 so that the circuit is connected successively to taps 1d, 1c, 1h and 1a. The contact arm 46 is rotated until the voltmeter (not shown) of the X-ray apparatus indicates that the increase of voltage of the supply circuit has been compensated for o-r the milliammeter 68 in the secondary circuit shows= the number of milliamperes for which the machine has been adjusted. If, however, the voltage of the supply circuit falls below its normal value, as is the case on overloaded circuits, the contact arm 46 is rotated clockwise from the fth position, as viewed in Figure 7 so that the circuit is connected successively to taps 1f, ig, 1h and 1i. In this manner differences of 10% above and below the normal voltage of the supply circuit may be compensated for. A total range of 20% compensation is thus provided. The taps can be arranged so that any percentage of voltage variations can be compensated for. This insures that the X-ray tube 3 operatesat all times under constant voltage ardized and pictures of uniform characteristics are obtained.

The foregoing described construction in which the circuit may be selectively connected to different taps of the primary winding of an X-ray transforme-r by means of a manually controlled regulating device may be applied to X-ray apparatus of many different kinds. In the embodirnent disclosed herein the tap changing apparatus is built into an X-ray apparatus in which the transformer only isysurrounded by oil. It will be understood that this apparatus may also be applied to an X-ray apparatus in which the transformer as Well as the X-ray tube are completely surrounded by oil. Instead of employing the herein described regulating device in which a contact arm is moved over a ring of contact members by means of an adjusting ring, regulating devices of a different type may be employed. The circuit may be connected to different taps on the primary winding by means of a button regulator that is similar to the button regulators employed in dental apparatus which would be mounted upon the housing that contains the transformer and the X-ray tube.

Since certain further changes may be made in the above construction and diierent embodiments of the invention may be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a. limiting sense.

I claim as my invention:

1. X-ray apparatus comprising, in combination, a housing disposed to be movably mounted, an X-ray tube mounted in said housing, a transformer mounted in said housing having a secondary winding connected to said X-ray tube and a prima-ry winding for connection to an alternating current circuit having a normal operating voltage, a plurality of taps on said primary winding, and a tap changing switch mounted in said housing and arranged and adapted to selectively connect said taps to said circuit in such manner as to cause said secondary winding to apply a predetermined voltage to said X-ray tube on slight change of the circuit voltage from said normal operating voltage as applied to said primary Winding.

2. X-ray apparatus comprising, in combination, a housing disposed to be movably mounted, an X-ray tube mounted in said housing, a transformer mounted in said housing having a secondary winding connected to said X-ray tube and a primary winding for connection to an alternating current circuit having a normal oper ating voltage, a plurality of taps on said primary winding, a tap changing switch mounted in said housing and arranged and adapted to selectively connect said taps to said circuit in such manner as to cause said secondary winding to apply a predetermined voltage to said X-ray tube on slight change of the circuit voltage from said normal operating voltage as applied to said primary winding, and externally operable means carried by said housing and operatively connected to said tap changing switch for operating the seme.

3. In X-ray apparatus, a housing disposed to be rotatably mounted, a plurality of stationary contact members arranged in a circle in said housing, a contact arm rotatably mounted in said housing for successively engaging said contact members, and rotatable adjustment means operatively connected to said contact arm and adapted to be moved exteriorly of and relative to said housing for rotating said contact arm, the axis of rotation of said adjusting means being coincident with the axis of rotation of said housing.

4. In X-ray apparatus, a housing disposed to be rotatably mounted, a plurality of stationary contact members arranged in a circle in said housing, a contact arm rotatably mounted in said housing for successively engaging said contact members, rotatable adjusting means operatively connected to said Contact arm and adapted to be moved exteriorly of and relative to said housing for rotating said contact arm, the axis of rotation of said adjusting means being coincident with the axis of rotation of said housing, and means causing said adjusting means to be stopped at positions corresponding to the various positions of said contact arm in individual engagement with said contact members.

5. In X-ray apparatus, a housing disposed to be rotatably mounted, a plurality of stationary contact members arranged in a circle in said housing, a contact arm rotatably mounted in.

said housing for successively engaging said ccntact members, rotatable adjusting means operatively connected to said contact arm and adapted to be moved exteriorly of and relative to said housing for rotating said contact arm, the axis of rotation of said adjusting means being coincident with the axis of rotation of said housing, means causing said adjusting means to be stopped at positions corresponding to the various positions of said contact arm in individual engagement with said contact members, and stop means limiting the rotation of said adjusting means in either direction.

6. In X-ray apparatus, a housing disposed to be movably mounted, a plurality of stationary contact members arranged in a circle in said housing, a contact arm rotatably mounted in said housing for successively engaging said contact members, a gear Wheel mounted in said housing for rotation With said Contact arm, and an adjusting ring rotatably mounted on said housing and having teeth on its inner periphery for driving said gear Wheel and adapted to be moved exteriorly of said housing for rotating said contact arm.

7. In X-ray apparatus, a housing disposed to be movably mounted, a plurality of stationary Contact members arranged in a circle in said housing, a contact arm rotatably mounted in said housing for successively engaging said contact members, a gear Wheel mounted in said housing for rotation with said contact arm, an adjusting ring rotatably mounted on said housing and having teeth on its inner periphery for driving said gear Wheel and adapted to be moved exteriorly of said housing for rotating said contact arm, and spring biased means cooperating with said adjusting ring and tending to stop the same at positions corresponding to the various positions of said contact arm in engagement with each of said contact members.

8. In X-ray apparatus, a housing disposed to be movably mounted, a plurality of stationary contact members arranged in a circle in said housing, a contact arm rotatably mounted in said housing for successively engaging said contact members, a gear Wheel mounted in said housing for rotation with said contact arm, an idler gear wheel meshing with said gear Wheel, an adjusting ring rotatably mounted on said housing having teeth extending inwardly along a portion of its inner periphery and meshing With said idler gear Wheel and having spaced recesses along another portion of its inner periphery each corresponding to one of said contact members, said adjusting ring being movable eX- teriorly of said housing, and a spring pressed member disposed to cooperate With said recesses for stopping said adjusting ring at positions corresponding to various positions of said contact arm in individual engagement with said contact members.

9. In X-ray apparatus, a housing disposed to be movably mounted, a plurality of stationary contact members arranged in a circle in said housing, a Contact arm rotatably mounted in said housing for successively engaging said contact members, a gear Wheel mounted in said housing for rotation with said contact arm, an idler gear Wheel meshing with said gear wheel, an adjusting ring rotatably mounted on said housing having teeth extending inwardly along a portion of its inner periphery and meshing with said idler gear Wheel and having spaced recesses along another portion of its inner periphery each corresponding to one of said contact members, said adjusting ring being movable exteriorly of said housing, a spring pressed member disposed to cooperate With said recesses for stopping said adjusting ring at positions corresponding to various positions of said contact arm in individual engagement With said contact members, and stop means cooperating with said adjusting ring for definitely limiting the rotation thereof in either direction.

10. X-ray apparatus comprising, in combination, a housing disposed to be movably mounted, an X-ray tube mounted in said housing, a transformer mounted in said housing having a secondary Winding connected to said X-ray tube and a primary Winding for connection to an alternating current circuit having a normal operating voltage, a plurality of taps on said primary winding, a plurality of stationary Contact members arranged in a circle in said housing and each connected to one of said taps, a contact arm rotatably mounted in said housing for successively engaging said contact members to selectively connect said taps to said circuit in such manner as to cause said secondary winding to apply a predetermined voltage to said X-ray tube on slight changes of the circuit voltage from said normal operating voltage as applied to said primary Winding, and a rotatable adjusting ring operatively connected to said Contact arm and adapted to be moved exteriorly of said housing for rotating said contact arm.

11. X-ray apparatus comprising, in combination, a housing disposed to be movably mounted, an X-ray tube mounted in said housing, a transformer mounted in said housing having a secondary Winding connected to said X-ray tube and a primary winding for connection to an alternating current circuit having a normal operating voltage, a plurality of taps on said primary winding, a plurality of stationary contact members arranged in a circle in said housing and each connected to one of said taps, a contact arm rotatably mounted in said housing for successively engaging said contact members to selectively connect said taps to said circuit in such manner as to cause said secondary winding to apply a predetermined voltage to said X-ray tube on slight changes of the circuit voltage from said normal operating voltage as applied to said primary Winding, a rotatable adjusting ring operatively connected to said contact arm and adapted to be moved exteriorly of said housing for rotating said contact arm, and means tending to stop said adjusting ring at positions corresponding to the various positions of said contact arm in individual engagement with said contact members.

12. X-ray apparatus comprising, in combination, a housing disposed to be movably mounted, an X-ray tube mounted in said housing, a transformer mounted in said housing having a secondary Winding connected to said X-ray tube and a primary Winding for connection to an alternating current circuit having a normal operating voltage, a plurality of taps on said primary winding, a plurality of stationary contact members arranged in a circle in said housing and each connected to one of said taps, a contact arm rotatably mounted in said housing for successively engaging said contact members to selectively connect said taps to said circuit in such manner as to cause said secondary winding to apply a predetermined voltage to said X-ray tube on slight changes of the circuit voltage from said normal operating voltage as applied to said primary winding, a gear wheel mounted in said housing for rotation with said contact arm, an idler gear wheel meshing with said gear wheel, an adjusting ring rotatably mounted on said housing having teeth extending inwardly along a portion of its inner periphery and meshing with said idler gear wheel and having spaced recesses along another portion of its inner periphery each corresponding to one of said contact members, said adjusting ring being movable exteriorly of said heusing, and a spring pressed member disposed to cooperate with said recesses for stopping said adjusting ring at positions corresponding to various positions of said contact arm in individual engagement with said contact members.

EDWARD J. RIES.

CERTIFICATE OF CORRECTION.

Patent No. 2,1LLO,595. December l5, 19.58.,

EDWARD J. RIEIS.

It is hereby certified that error appears in the above numbered patent requiring correction as follows: In the heading to the drawings, line 5, for the filing dat@ "Nevu 5, i957" read may 5, 1957; and in the printed specification, page LL, first column, line ll, claim 5, for the word "adjustment" read adjusting,- and that the said Letters Patent should be read with this oorrection'therein that the csame may conform to the record of the Case in the Patent office.

signed and' sealed this 51st day of January, A. D. 1959.,y

Henry Van Arsda'le (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION. Patent No. 2,1LLo,593. i December 15, lagig,

EDWARD J. RIES.

It is hereby certified that error appears in the above numbered patent requiring correction as -follows: In the heading to the drawings, line 5, for the filing; date "1 \Iov.l 5, 1957" read -May 5, 1957; and in the printed specification, page h, first column, line ll, claim 5, for the word "adjustment" read adjusting; and that the said Letters Patent should be read with this correctionV therein that the (same may conform to the .record ofl the case in the Patent Office. 4

Signed and sealed this 51st day of January, A. D. 1959a I Henry Van Arsdale (Seal) Acting Commissioner of Patents 

